Self-aware composite mechanical metamaterials and method for making same

ABSTRACT

A self-aware composite mechanical metamaterial, comprising first and second electrically conductive components disposed relative to each other to act as opposite electrodes to induce contact electrification; wherein the first and second electrically conductive components, along with a dielectric component serving as a skeleton of the self-aware composite mechanical metamaterial, form a lattice of snapping curved semicircular-shaped segments, wherein each of the snapping curved semicircular-shaped segments has an elastic snap-through instability mechanism; and wherein the lattice comprises periodic repeatable parallel rows of the snapping curved semicircular-shaped segments.

RELATED APPLICATION

This application is a continuation-in-part of: Ser. No. 17/369,640 filedJul. 7, 2021 SELF-AWARE COMPOSITE MECHANICAL METAMATERIALS AND METHODFOR MAKING SAME which claims benefit of, and priority to: U.S.Provisional Application No. 63/048,943 filed Jul. 7, 2020, the entirespecification of each such application is incorporated herein byreference.

FIELD OF THE DISCLOSURE Technical Field

The present disclosure generally relates to the field of mechanicalmetamaterials and methods.

Background

The next generation of materials preferably will be adaptive,multifunctional and tunable. This goal can be achieved by metamaterialsthat enable development of advanced artificial materials with novelfunctionalities. During the last few years, the emerging concept ofstructure-dominated mechanical metamaterials (MMs) has receivedincreasing attention. MMs gain their tailoredunprecedented/counterintuitive mechanical properties from theirrationally-designed structures rather than inheriting them directly fromtheir chemical composition. The main reason for developing MMs is toengineer materials with unique properties that are not found innaturally occurring materials. Additive manufacturing has been a majordriving force in the exploration of MMs since virtually any topology canbe obtained to probe the vast design space created by geometric changesin the material structure. However, a substantial portion of the currenteffort in the arena of MMs has been merely going into exploring newgeometrical design of micro/nano-architectures to improve or identifyunusual sets of mechanical properties. Currently, there is a criticalshortage in research needed to engineer new aspects of intelligence intothe texture of mechanical metamaterials for multifunctionalapplications. In this context, the next stage of this technologicalrevolution is development of self-aware MMs that can sense, empower andprogram themselves. To address this challenge, the present disclosureintroduces a new class of multifunctional MMs that offers new sensingand energy harvesting functionalities in addition to the enhancedmechanical properties of “classical MMs”.

BRIEF SUMMARY OF THE DISCLOSURE

In a preferred aspect, the present disclosure comprises a self-awarecomposite mechanical metamaterial, comprising: first and secondelectrically conductive components disposed relative to each other toact as opposite electrodes to induce contact electrification; whereinthe first and second electrically conductive components, along with adielectric component serving as a skeleton of the self-aware compositemechanical metamaterial, form a lattice of snapping curvedsemicircular-shaped segments, wherein each of the snapping curvedsemicircular-shaped segments has an elastic snap-through instabilitymechanism; and wherein the lattice comprises periodic repeatableparallel rows of the snapping curved semicircular-shaped segments.

In another preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, the first and secondelectrically conductive components are embedded in the dielectriccomponent.

In yet another preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, a structure of the self-awarecomposite mechanical metamaterial forms a composite matrix of theelectrically conductive and dielectric components in a periodic manner.

In another preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, each of the snapping curvedsemicircular-shaped segments comprises a portion of each of the firstelectrically conductive component, the second electrically conductivecomponent and the dielectric component.

In yet another preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, opposing, parallel ends of thelattice are bound to respective supporting members.

In another preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, the lattice comprises a 5 by 5array of the snapping curved semicircular-shaped segments.

In yet another preferred aspect, a medical implant comprises theself-aware composite mechanical metamaterial of the present disclosure.

In another preferred aspect of a medical implant comprising theself-aware composite mechanical metamaterial of the present disclosure,the medical implant comprises a spinal fusion cage, an acetabular cup ora tibial tray.

In yet another preferred aspect, a medical stent comprises theself-aware composite mechanical metamaterial of the present disclosure.

In another preferred aspect of a medical stent comprising the self-awarecomposite mechanical metamaterial of the present disclosure, the medicalstent comprises a cardiovascular stent or an esophageal stent.

In yet another preferred aspect, a shock absorber comprises theself-aware composite mechanical metamaterial of the present disclosure.

In yet another preferred aspect, a concrete system comprises theself-aware composite mechanical metamaterial of the present disclosureand further comprises a conductive cementitious material and an auxeticpolymer lattice.

In another preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, the electrically conductivecomponents comprise polylactic acid.

In a further preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, the electrically conductivecomponents comprise carbon black.

In another preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, the electrically conductivecomponents comprise polylactic acid and/or carbon black.

In a further preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, the dielectric componentcomprises polyurethane.

In another preferred aspect of a self-aware composite mechanicalmetamaterial of the present disclosure, the electrically conductivecomponents comprise polylactic acid and carbon black and the dielectriccomponent comprises polyurethane.

In another preferred aspect, the present disclosure comprises a methodof manufacturing a self-aware composite mechanical metamaterialcomprising first and second electrically conductive components disposedrelative to each other to act as opposite electrodes to induce contactelectrification; wherein the first and second electrically conductivecomponents, along with a dielectric component serving as a skeleton ofthe self-aware composite mechanical metamaterial, form a lattice ofsnapping curved semicircular-shaped segments, wherein each of thesnapping curved semicircular-shaped segments has an elastic snap-throughinstability mechanism; and wherein the lattice comprises periodicrepeatable parallel rows of the snapping curved semicircular-shapedsegments, comprising using 3D printing or other additive manufacturingprocess employing multi-material filaments to produce the latticecomprising periodic repeatable parallel rows of the snapping curvedsemicircular-shaped segments.

In yet another preferred aspect, the present disclosure comprises anenergy harvester comprising a self-aware composite mechanicalmetamaterial, comprising first and second electrically conductivecomponents disposed relative to each other to act as opposite electrodesto induce contact electrification; wherein the first and secondelectrically conductive components, along with a dielectric componentserving as a skeleton of the self-aware composite mechanicalmetamaterial, form a lattice of snapping curved semicircular-shapedsegments, wherein each of the snapping curved semicircular-shapedsegments has an elastic snap-through instability mechanism; and whereinthe lattice comprises periodic repeatable parallel rows of the snappingcurved semicircular-shaped segments.

In yet another preferred aspect, a sensor comprises the self-awarecomposite mechanical metamaterial of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

For the present disclosure to be easily understood and readilypracticed, the present disclosure will now be described for purposes ofillustration and not limitation in connection with the followingfigures, wherein:

FIG. 1 shows visions of the proposed multifunctional MM concept of thepresent disclosure for active sensing and energy harvesting: FIG. 1shows in (a) a preferred composition of a “self-aware compositemechanical metamaterial” (SCMM) system of the present disclosure; FIG. 1shows in (b) a preferred flying wing aircraft with self-diagnostic andenergy harvesting wings made of a network of SCMM structures; and FIG. 1shows in (c) a preferred self-powered and self-sensing cardiovascularstent using a preferred SCMM of the present disclosure for continuousmonitoring of the artery radial pressure changes due to tissueovergrowth;

FIG. 2 shows power density for different available energy harvestingmodalities;

FIG. 3A shows a segment of the conductive layers of a preferred 2D MMwith parallel semicircular-shaped snapping segments of the presentdisclosure;

FIG. 3B shows two conductive layers created as 5 periodic repeatablesegments of a preferred 2D MM with parallel semicircular-shaped snappingsegments of the present disclosure;

FIG. 3C shows aligned conductive layers of a preferred 2D MM withparallel semicircular-shaped snapping segments of the presentdisclosure;

FIG. 3D shows the geometry of a preferred unit cell composed of theconductive layers and dielectric layers that are involved in thecontact—separation process of a preferred 2D MM with parallelsemicircular-shaped snapping segments of the present disclosure;

FIG. 3E and FIG. 3F show representations of the entire composite matrixof the a preferred SCCM of the present disclosure composed of twoconductive layers and dielectric layers in a periodic manner in apreferred 2D MM with parallel semicircular-shaped snapping segments ofthe present disclosure;

FIG. 3G shows a preferred manner of 3D printing a preferred SCCM of thepresent disclosure;

FIG. 4A shows a preferred self-sensing and self-charging 2D SCMM of thepresent disclosure with a 5×5 array of unit cells 20;

FIG. 4B shows a preferred SCCM of the present disclosure in thecompacted state;

FIG. 4C shows preferred snapping mechanisms of elastic bulkingsemicircular-shaped snapping shells of the present disclosure;

FIG. 4D shows applied cyclic loads and the corresponding voltagegenerated by a preferred SCCM of the present disclosure.

FIG. 5A shows a preferred embodiment of a SCMM medical implant, such asorthopedics implants (spinal fusion cages, acetabular cups, tibialtrays, etc) of the present disclosure;

FIG. 5B shows a preferred embodiment of a cardiovascular stentincorporating an SCMM of the present disclosure;

FIG. 5C shows a preferred embodiment of an esophageal stentincorporating an SCMM of the present disclosure;

FIG. 6 shows a preferred embodiment of a shock absorber incorporating anSCMM of the present disclosure.

FIG. 7 shows a preferred embodiment of a concrete system incorporatingan SCMM of the present disclosure

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying examples and figures that form a part hereof, and in whichis shown, by way of illustration, specific embodiments in which theinventive subject matter may be practiced. These embodiments aredescribed in sufficient detail to enable those skilled in the art topractice them, and it is to be understood that other embodiments may beutilized and that structural or logical changes may be made withoutdeparting from the scope of the inventive subject matter. Suchembodiments of the inventive subject matter may be referred to,individually and/or collectively, herein by the term “disclosure” merelyfor convenience and without intending to voluntarily limit the scope ofthis application to any single inventive concept if more than one is infact disclosed.

The following description is, therefore, not to be taken in a limitedsense, and the scope of the inventive subject matter is defined by theappended claims and their equivalents.

The present disclosure is directed to a new generation of composite MMscalled “self-aware composite mechanical metamaterial (SCMM)” withcomplex internal structures toward achieving self-sensing andself-powering functionalities along with the boosted mechanicalproperties. The present disclosure is based on the following: (a) finelytailored and seamlessly integrated microstructures composed oftopologically different triboelectric materials can form a hybrid MMsystem that can both harvest the energy from the external mechanicalexcitations and measure various levels of the forces applied to itsstructure; and (b) a composite MM composed of different materials thatare organized in a periodic manner will boost the mechanical propertiessuch as strength and stiffness. The feasibility of the SCMM concept ofthe present disclosure has been demonstrated for designing ametamaterial structure with active sensing and energy harvestingfunctionalities. The results have led to the grand vision for thepresent disclosure (shown in FIG. 1), where architecture tailoring ofmaterials via additive manufacturing could form a new class ofmultifunctional MMs for a broad range of applications. FIG. 1 showsvisions of the proposed multifunctional MM concept of the presentdisclosure for active sensing and energy harvesting: FIG. 1 shows in (a)a preferred composition of the SCMM system 10 of the present disclosure.FIG. 1 shows in (b) a flying wing aircraft with self-diagnostic andenergy harvesting wings made of a network of SCMM structures 10. FIG. 1shows in (c) a self-powered and self-sensing cardiovascular stent usingSCMM 10 for continuous monitoring of the artery radial pressure changesdue to tissue overgrowth. Deformation mode of the fabricatedmicrostructures of the present disclosure preferably are engineeredthrough a unique design so that contact electrification will occurbetween the two surfaces as the SCMM structure undergoes periodicdeformations due to mechanical excitations. The SCMM contacting/slidingsurfaces of the present disclosure will act as conductive and dielectriclayers as shown in FIG. 1 at (a). Due to the contact electrification,the conductive and dielectric layers will accumulate positive andnegative charges, respectively. As the SCMM structure of the presentdisclosure is unloaded, the transferred charge will remain on thedielectric surface. This will form a static electric field and apotential difference between the conductive layers. By increasing theloading amplitude, more conductive and dielectric layers of the SCMMmatrix of the present disclosure will get involved in thecontact—separation process, which will result in generating higherelectrical output. The electrical output signals can be used for activesensing of the external mechanical excitation applied to the SCMMstructure of the present disclosure. On the other hand, the generatedelectrical energy can be harvested and stored to empower sensors andelectronics at low power.

The goal of the present disclosure is to advance the knowledge andtechnology required to create a new class of multifunctional MMs systemsthat offer self-sensing, self-monitoring, and energy harvestingproperties along with boosted mechanical performance due to theircomposite structure.

The present disclosure preferably will aid in the discovery of materialswith new properties and functionalities in the fields of aerospace(morphing/deployable space structures), biomedical devices (medicalimplants, stents, artificial muscles), civil infrastructure andconstruction. From a sensing perspective, introducing the self-sensingfunctionality into the MM design could in theory lay the foundations forliving structures that respond to their environment and self-monitortheir condition. The present disclosure preferably is directed to“self-aware structures” where structural systems utilize their entireconstituent components as a sensing medium to directly infer multipletypes of hidden information relating to the structure. In addition toits “inferring itself” aspects, the present disclosure has numerousapplications in the structural health monitoring arena. Traditionalstructural health monitoring approaches use dedicated sensors whichoften results in dense and heterogeneous sensing systems that aredifficult to install and maintain in large-scale structures. On theother hand, it is not always possible embed a traditional sensor (suchas a strain gauge) inside structures such as, in which cross-sectionalor interlaminate failures may not be observable at the surface. Anotherbottleneck limiting the structural health monitoring applications isthat permanent monitoring systems often require extensive maintenance asa consequence of the limited durability of traditional sensors and ofthe limited robustness and exposure to failures of typical structuralhealth monitoring architectures. The present disclosure can address mostof these challenges because it is a paradigm shift in technology wherestructure can be a sensing medium itself through a rationalarchitectural design and choice of constituent materials. In addition toits self-sensing features, an SCMM system of the present disclosure isintrinsically sensitive to the applied stresses, and therefore, it canbe implemented as a sensor in various materials or structural systems.

From an energy harvesting perspective, the present disclosure offers newconcepts and mechanisms for materials and structures that utilize theenergy that develops within them (strain and kinetic energy) forself-powering or local powering of sensing and actuating devices.

From a mechanical perspective, SCMMs of the present disclosure arepreferably composed of different materials that are organized in aperiodic manner. Therefore, SCMMs of the present disclosure not onlyinherit all features of classical MMs but could also offer significantlyboosted mechanical properties due to their composite structure byovercoming the “rule of mixtures”. In accordance with the presentdisclosure, mechanical properties of SCMMs are preferably predicted andtuned the to make them programmable tools for various engineeringapplications.

The performance of a two-dimensional (2D) snapping MMs 10 designedaccording to the SCMM concept of the present disclosure has beenanalyzed. An architected MM 10 containing parallel snapping curved(semicircular-shaped) segments 12, 14 with elastic snap-throughinstability mechanism was fabricated according to the presentdisclosure. Multi-stable/self-recovering snapping metamaterials haveadvantages in applications such as the development of tunablemetamaterials with switchable properties. According to the presentdisclosure, the metamaterial was made up of multiple bi-stable unitcells 20. The unit cell 20 consisted of thick horizontal and verticalelements and a thin curved part. In order to incorporate the sensing andenergy harvesting features into the metamaterial functionality of theSCMM 10 of the present disclosure, the triboelectrification phenomenonwas incorporated into its architecture design. The triboelectrificationphenomenon is a universally-existing phenomenon in the nature andpeople's living life and has been known for thousands of years. Itdescribes a contact electrification phenomenon that a material/surfacebecomes electrically charged after it gets into contact with a differentmaterial/surface. The design process is shown in FIGS. 3A-3G.

FIGS. 3A-3G show the designing of a 2D MM with parallelsemicircular-shaped snapping segments according to the SCMM concept ofthe present disclosure. FIG. 3A shows a segment 11 of the conductivelayers 12, 14 of a preferred 2D MM with parallel semicircular-shapedsnapping segments of the present disclosure. FIG. 3B shows the twoconductive layers 12, 14 created as 5 periodic repeatable segments. FIG.3C shows aligned conductive layers 12, 14 of a preferred 2D MM withparallel semicircular-shaped snapping segments of the presentdisclosure. FIG. 3D shows the geometry of a symmetric unit cell 20composed of the conductive layers 12, 14 and dielectric layers 16 thatare involved in the contact—separation process of a preferred 2D MM withparallel semicircular-shaped snapping segments of the presentdisclosure. FIG. 3E and FIG. 3F show a schematic representation of theentire composite matrix of the SCCM 10 composed of the conductive layers12, 14 and dielectric layers 16 in a periodic manner in a preferred 2DMM with parallel semicircular-shaped snapping segments of the presentdisclosure. FIG. 3G shows a preferred manner of 3D printing a SCCM 10 ofthe present disclosure.

In order to fabricate the 2D structure of the snapping SCMM of thepresent disclosure, three constituent layers were defined. The first twolayers were conductive layers 12, 14 created as periodic repeatablesegments 20 (FIGS. 3A-3B). The conductive layers 12, 14 were firstaligned to act as opposite electrodes. Then, they were embedded inside athicker dielectric layer 16 serving as the skeleton of the MM (FIG. 3D).As seen in FIGS. 3D-3F, the entire snapping SCMM structure 10 of thepresent disclosure forms composite matrix composed of the conductivelayers 12, 14 and dielectric layers 16 in a periodic manner. Thesemicircular-shaped snapping segments include both conductive layers 12,14 and dielectric layers 16 (FIG. 3D). The semicircular-shaped snappingsegments 20 were centrally clamped by relatively thicker (stiffer)supporting segments 30 with a connection platform, as illustrated inFIGS. 3D-3E.

Preferably, the curved elements were specifically designed inmathematical/trigonometric function form to achieve smooth snap-throughtransition and symmetrical stable configurations before and after largedeformation. In order to fabricate this complex design as one integratedunit, Raise3D Pro2 Dual Extruder 3D Printer was used as it supportsprinting with a variety of multi-material filaments. There is a widerange of organic and inorganic materials from the triboelectric seriesthat can be used to fabricate the conductive and dielectric layers ofthe SCMM of the present disclosure. Preferably, materials with a largedifference in triboelectric polarity are used to maximize theelectrification between the two layers. Polylactic Acid (PLA) withcarbon black (Young's modulus E=3000 MPa, Poisson's ratio ν=0.48) andThermoplastic Polyurethane (TPU) (E=12 MPa, ν=0.25) were used as theconductive and dielectric layers, respectively.

The test setup and the fabricated SCMM of the present disclosure areshown in FIG. 3G and FIGS. 4A-4B. Uniaxial loading experiments wereperformed on the 3D printed metamaterial specimen SCCM 10 of the presentdisclosure with a TestResources testing machine 40. Cycling loading at0.5 Hz frequency was applied to the specimen SCCM 10 under displacementcontrol until it was fully compacted. The displacement range wascontrolled to be between 5 mm to 10 mm. The applied load changed between15N and 45N. Under uniaxial loading, the SCCM 10 undergoes a largedeformation caused by stiffness mismatch between snapping (bucklinginstabilities) and supporting (relatively stiffer/thicker) components,exhibiting very small transverse deformation after every snapping. Basedon the multi-stable/self-recovering mechanism, phasetransformation/shape-reconfiguration and zero (or close to zero)Poisson's ratio can be achieved up to large morphological change (FIG.4B).

As shown in FIG. 4C, when a normal vertical force applied in the middleof the curved beams, the semicircular-shaped segment is mechanicallydeformed (buckled), snapping from first/original stable state (State I)to second/deformed stable state (State IV) at a critical applied force.In a very ideal situation, the constrained conditions at both ends arestrong and the two stable states are symmetric, the reaction force willbe symmetric from one to the other stable state under displacementcontrol which means that an identical reverse force is needed thatallows the deformed beams to return to their original configuration. Inthe case of a self-recovering snapping, the constant positive forcemeans that the snapped segments (State IV) automatically return to theirinitial stable configuration (State I) after the load is removed. Undercompressive loads, the SCCM 10 of the present disclosure undergoesperiodic deformations and contact electrification occurs between theconductive layers 12, 14 and dielectric layers 16. By unloading the SCCM10, a potential difference is formed between the conductive layers 12,14. Higher loading amplitude results in larger deformations.Consequently, more conductive layers 12, 14 and dielectric layers 16 ofthe matrix of SCCM 10 get involved in the contact—separation process.This leads to higher rate of the electrostatically-induced electrontransfer and generating higher voltage. In order to record the voltagegenerated due to the applied mechanical excitations, wires 50, 52 wereconnected to the extended parts of the conductive layers, as shown inFIG. 4A. The voltage values were read using a National Instruments 9220DAQ module with 1 GΩ impedance. The applied cyclic loads and thecorresponding voltage generated by the proposed mechanical metamaterialstructure are shown in FIG. 4D. As seen, the voltage is proportional tothe applied force. Also, the generated electrical energy can be readilystored using an energy harvesting circuit.

FIG. 4A shows a preferred self-sensing and self-charging 2D SCMM 10 ofthe present disclosure with a 5×5 array of unit cells 20. FIG. 4B showsthe SCCM 10 in the compacted state. FIG. 4C shows preferred snappingmechanisms of elastic bulking semicircular-shaped snapping shells of thepresent disclosure. FIG. 4D shows applied cyclic loads and thecorresponding voltage generated by the SCCM 10.

According to the present disclosure, it is feasible to create SCMMs 10with sensing and energy harvesting functionalities via introducing thecontact electrification into the fabrication process. Preferably, theSCMMs 10 of the present disclosure will allow for measuring the forceapplied to the SCMM 10 by monitoring the voltage generated therefrom.The kinetic energy harvested from the external excitations of the SCMM10 can be stored for self-powering or empowering other sensing devices.Furthermore, the SCMMs 10 of the present disclosure allow for thecreation of MMs whose mechanical and electrical response can beprogrammed. Preferably, the snapping mechanism or the layered design ofthe composite matrix of the SCMMs 10 of the present disclosure can beengineered to deform in specified order or prevent random snapping,which will result in programmed triboelectrification and mechanicalbehaviors. Preferably, the SCMMs 10 of the present disclosure can beapplied to design a variety of programmable MMs with sensing, energyharvesting properties.

As shown in FIG. 5A, medical implants 60, such as orthopedics implants(spinal fusion cages, acetabular cups, tibial trays, etc.), preferablyincorporate an SCCM 10 of the present disclosure.

As shown in FIG. 5B and FIG. 5C, respectively, cardiovascular stents 70and esophageal stents 80 also preferably incorporate an SCCM 10 of thepresent disclosure.

As shown in FIG. 6, shock absorbers 90 preferably incorporate an SCCM 10of the present disclosure.

As shown in FIG. 7, concrete systems 100 comprising conductivecementitious material 102 and an auxetic polymer lattice 104 preferablyincorporate SCCMs 10 of the present disclosure.

In the foregoing Detailed Description, various features are groupedtogether in a single embodiment to streamline the disclosure. Thismethod of disclosure is not to be interpreted as reflecting an intentionthat the claimed embodiments of the disclosure require more featuresthan are expressly recited in each claim. Rather, as the followingclaims reflect, inventive subject matter lies in less than all featuresof a single disclosed embodiment. Thus, the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separate embodiment.

What is claimed is:
 1. A self-aware composite mechanical metamaterial,comprising: first and second electrically conductive components disposedrelative to each other to act as opposite electrodes to induce contactelectrification; wherein the first and second electrically conductivecomponents, along with a dielectric component serving as a skeleton ofthe self-aware composite mechanical metamaterial, form a lattice ofsnapping curved semicircular-shaped segments, wherein each of thesnapping curved semicircular-shaped segments has an elastic snap-throughinstability mechanism; and wherein the lattice comprises periodicrepeatable parallel rows of the snapping curved semicircular-shapedsegments.
 2. The self-aware composite mechanical metamaterial of claim1, wherein the first and second electrically conductive components areembedded in the dielectric component.
 3. The self-aware compositemechanical metamaterial of claim 1, wherein a structure of theself-aware composite mechanical metamaterial forms a composite matrix ofthe electrically conductive and dielectric components in a periodicmanner.
 4. The self-aware composite mechanical metamaterial of claim 1,wherein each of the snapping curved semicircular-shaped segmentscomprises a portion of each of the first electrically conductivecomponent, the second electrically conductive component and thedielectric component.
 5. The self-aware composite mechanicalmetamaterial of claim 1, wherein opposing, parallel ends of the latticeare bound to respective supporting members.
 6. The self-aware compositemechanical metamaterial of claim 1, wherein the lattice comprises a 5 by5 array of the snapping curved semicircular-shaped segments.
 7. Amedical implant comprising the self-aware composite mechanicalmetamaterial of claim
 1. 8. The medical implant of claim 7, wherein themedical implant comprises a spinal fusion cage, an acetabular cup or atibial tray.
 9. A medical stent comprising the self-aware compositemechanical metamaterial claim
 1. 10. The medical stent of claim 9,wherein the medical stent comprises a cardiovascular stent or anesophageal stent.
 11. A shock absorber comprising the self-awarecomposite mechanical metamaterial of claim
 1. 12. A concrete system,comprising the self-aware composite mechanical metamaterial of claim 1and further comprising a conductive cementitious material and an auxeticpolymer lattice.
 13. The self-aware composite mechanical metamaterial ofclaim 1, wherein the electrically conductive components comprisepolylactic acid and/or carbon black.
 14. The self-aware compositemechanical metamaterial of claim 1, wherein the dielectric componentcomprises polyurethane.
 15. The self-aware composite mechanicalmetamaterial of claim 1, wherein the electrically conductive componentscomprise polylactic acid and carbon black and the dielectric componentcomprises polyurethane.
 16. The self-aware composite mechanicalmetamaterial of claim 2, wherein the electrically conductive componentscomprise polylactic acid and carbon black and the dielectric componentcomprises polyurethane.
 17. The self-aware composite mechanicalmetamaterial of claim 3, wherein the electrically conductive componentscomprise polylactic acid and carbon black and the dielectric componentcomprises polyurethane.
 18. A method of manufacturing a self-awarecomposite mechanical metamaterial comprising first and secondelectrically conductive components disposed relative to each other toact as opposite electrodes to induce contact electrification; whereinthe first and second electrically conductive components, along with adielectric component serving as a skeleton of the self-aware compositemechanical metamaterial, form a lattice of snapping curvedsemicircular-shaped segments, wherein each of the snapping curvedsemicircular-shaped segments has an elastic snap-through instabilitymechanism; and wherein the lattice comprises periodic repeatableparallel rows of the snapping curved semicircular-shaped segments,comprising: using 3D printing or other additive manufacturing processemploying multi-material filaments to produce the lattice comprisingperiodic repeatable parallel rows of the snapping curvedsemicircular-shaped segments.
 19. An energy harvester comprising aself-aware composite mechanical metamaterial, comprising: first andsecond electrically conductive components disposed relative to eachother to act as opposite electrodes to induce contact electrification;wherein the first and second electrically conductive components, alongwith a dielectric component serving as a skeleton of the self-awarecomposite mechanical metamaterial, form a lattice of snapping curvedsemicircular-shaped segments, wherein each of the snapping curvedsemicircular-shaped segments has an elastic snap-through instabilitymechanism; and wherein the lattice comprises periodic repeatableparallel rows of the snapping curved semicircular-shaped segments.
 20. Asensor comprising the self-aware composite mechanical metamaterial ofclaim 1.